Effect of surface treatment and resin cement type on the bond strength of polyetheretherketone to lithium disilicate ceramic

BACKGROUND

This study aims to evaluate the effect of surface treatment and resin cement on the shear bond strength (SBS) and mode of failure of polyetheretherketone (PEEK) to lithium disilicate ceramic (LDC). This is suggested to study alternative veneering of PEEK frameworks with a ceramic material.

METHODS

eighty discs were prepared from PEEK blank and from lithium disilicate ceramic. Samples were divided into four groups according to surface treatment: Group (A) air abraded with 110 μm Al2O3, Group (AP) air abrasion and primer application, Group (S) 98% sulfuric acid etching for 60 s, Group (SP) Sulfuric acid and primer. Each group was subdivided into two subgroups based on resin cement type used for bonding LDC:1) subgroup (L) self- adhesive resin cement and 2) subgroup (B) conventional resin cement (n = 10). Thermocycling was done for all samples. The bond strength was assessed using the shear bond strength test (SBS). Failure mode analysis was done at 50X magnification with a stereomicroscope. Samples were chosen from each group for scanning electron microscope (SEM). The three-way nested ANOVA followed by Tukey's post hoc test were used for statistical analysis of results. Comparisons of effects were done utilizing one way ANOVA and (p < 0.05).

RESULTS

The highest mean of shear bond strength values was demonstrated in Group of air abrasion with primer application using conventional resin cement (APB) (12.21 ± 2.14 MPa). Sulfuric acid groups showed lower shear bond strength values and the majority failed in thermocycling especially when no primer was applied. The failure mode analysis showed that the predominant failure type was adhesive failure between cement and PEEK, while the remaining was mixed failure between cement and PEEK.

CONCLUSION

The air abrasion followed by primer application and conventional resin cement used for bonding Lithium Disilicate to PEEK achieved the best bond strength. Primer application did not have an effect when self-adhesive resin cement was used in air-abraded groups. Priming step is mandatory whenever sulfuric acid etching surface treatment is utilized for PEEK.

Assessment of a novel electrochemically deposited smart bioactive trabecular coating (SBTC®): a randomized controlled clinical trial

OBJECTIVES

A randomized controlled clinical trial of dental implants was conducted to compare the clinical properties of a novel electrochemically deposited calcium phosphate coating to those of a common marketed surface treatment.

MATERIAL AND METHODS

Forty implants of the same brand and type were placed in 20 fully edentulous participants requiring mandibular implantation. The two study groups were defined by the surface treatment of the implants. 20 implants in the control group were coated via a commercial electrochemical surface treatment that forms a mixture of brushite and hydroxyapatite, while the remaining 20 in the test group were coated with a novel electrochemical Smart Bioactive Trabecular Coating (SBTC®). A split-mouth design was employed, with each participants receiving one control implant in one mandibular side and a test implant in the other. To mitigate potential operator-handedness bias, control and test implants were randomly assigned to mandibular sides. All cases underwent digital planning, implant placement with a static surgical guide, and participants received locator-anchored full-arch dentures. The primary outcome was implant stability (measured using Osstell ISQ) assessed at insertion, loading, and then 3 months, 9 months, and 2 years post-insertion. The secondary outcome was bone level change (in millimeters) over the 2-year observation period. Oral health-related quality of life (OHRQL) was monitored using the OHIP-14 questionnaire. Complications and adverse events were recorded.

RESULTS

Successful osseointegration and implant stability were achieved in all cases, allowing loading. ISQ values steadily increased throughout the observation period. While no significant differences were observed between the SBTC® and control coatings, the test group exhibited a higher ISQ gain. Bone resorption was somewhat lower in the SBTC® but not significantly so. Patients' OHRQL significantly improved after denture delivery and remained stable throughout the follow-up. No complications or adverse events were observed.

CONCLUSIONS

Based on the study results, we conclude that the new surface treatment is a safe alternative to the widely used control surface, demonstrating similar osseointegrative properties and time-dependent bone level changes. Further research may explore the broader implications of these findings.

TRIAL REGISTRATION

The study is registered on clinicaltrials.gov under the identifier ID: NCT06034171.

How the repair bonding strength of hybrid ceramic CAD/CAM blocks is influenced by the use of surface treatments and universal adhesives

We examined how different methods of surface treatment and different universal adhesives with or without extra silane affected the repair bonding strength of hybrid ceramic CAD/CAM restorations. Cerasmart specimens (n=320) were subjected to thermocycling and assigned to the following surface pretreatment protocols: control, diamond bur (DB), hydrofluoric acid (HF), and tribochemical silica coating (TSC). Half the specimens received a coating of silane, followed by application of the universal adhesives Futurabond M+ (FMU), Tokuyama Universal Bond (TUB), Single Bond Universal (SBU), or Clearfil Universal Bond Quick (CUQ) (n=10). A hybrid composite resin was used to simulate repair; then the specimens underwent further thermocycling. Shear bond strength (SBS) was determined and modes of failure were examined. The TSC-CUQ silane (-) group showed the highest SBS values. The best repairs were obtained when the surface was treated with TSC, with the exception of the DB-TUB silane (-) group. TUB increased SBS more than the other adhesives. Additional silane decreased SBS in the HF-TUB and TSC-CUQ groups, while increasing it in the TSC-TUB and DB-FMU groups (p<0.05).

Fracture strength of porcelain veneer on surface-treated zirconia

In this study, we investigated the effects of surface treatment on the fracture strength of porcelain-veneered zirconia. Highly translucent 4 mol% yttria-stabilized zirconia disks (KATANA HT, Kuraray Noritake Dental) were divided into three surface-treatment groups: 1)as-sintered, 2) alumina sandblasted, and 3) ground. Crystallographic and surface-roughness analyses were conducted for each group. Veneering ceramics (Cerabien ZR, Kuraray Noritake Dental) were applied to the zirconia surfaces. The fracture strengths of the porcelain-veneered zirconia disks were measured using biaxial flexural-strength tests. Crystallographic analysis revealed that grinding and sandblasting increased the fractions of the monoclinic and rhombohedral zirconia phases. The ground specimens had a higher surface roughness than the sandblasted specimens. Weibull analysis showed no significant differences in biaxial flexural strength among the three groups. The results suggest that these surface treatments do not affect the fracture strength of porcelain-veneered zirconia.

Research progress of metal biomaterials with potential applications as cardiovascular stents and their surface treatment methods to improve biocompatibility

Facing the growing issue of cardiovascular diseases, metallic materials with higher tensile strength and fatigue resistance play an important role in treating diseases. This review lists the advantages and drawbacks of commonly used medical metallic materials for vascular stents. To avoid post-procedural threats such as thrombosis and in-stent restenosis, surface treatments, and coating methods have been used to further improve the biocompatibility of these materials. Surface treatments including laser, plasma treatment, polishing, oxidization, and fluorination can improve biocompatibility by modifying the surface charges, surface morphology, and surface properties of the material. Coating methods based on polymer coatings, carbon-based coatings, and drug-functional coatings can regulate the surface properties, and also serve as an effective barrier to the interaction of metallic biomaterial surfaces with biomolecules, which can be used to improve corrosion resistance and stability, as well as improve their biocompatibility. Biocompatibility serves as the most fundamental property of cardiovascular stents, and maintaining the excellent and stable biocompatibility of cardiovascular stent surfaces is a current research bottleneck. Few reviews have been published on metallic biomaterials as cardiovascular stents and their surface treatments. For the purpose of advancing research on cardiovascular stents, common metal biomaterials, surface treatment methods, and coating methods to improve biocompatibility and comprehensive properties of the materials are described in this review. Finally, we suggest future directions for stent development, including continuously improving the durability and stability of permanent stents, accelerating the development of biodegradable stents, and strengthening feedback to improve the safety and reliability of cardiovascular stents.

Effect of zirconia surface conditioning before glazing on the wear of opposing enamel: an in vitro study

OBJECTIVES

This in vitro study aimed to evaluate the wear of natural teeth opposing 3 mol% yttria-stabilized tetragonal zirconia polycrystal (3Y-TZP) with different surface conditions.

MATERIALS AND METHODS

Sixty 3Y-TZP specimens were randomly assigned to six groups (n = 10), differing in surface condition. In three groups, the samples underwent glazing-with the glaze applied to roughened (i.e., 106-µm-grit diamond-finished), as-sintered, and polished zirconia. The three remaining groups consisted of unglazed specimens: solely polished samples and diamond-finished samples (106-µm-grit and 46-µm-grit) without further conditioning. Two-body wear was evaluated at extracted, non-carious molars (n = 60), which served as antagonists in chewing simulation (10,000 masticatory cycles, 49N load). As a control, natural teeth with intact enamel surfaces were tested against natural molars (n = 10). All samples were 3D-scanned before and after the chewing simulation (7 Series, Straumann). Volume loss was calculated (Inspect Software, GOM), and statistically analyzed (SPSS Statistics 24, IBM).

RESULTS

Volume loss of the natural antagonists decreased in the following order: 106-µm-grit diamond-finished zirconia (4.6 ± 2.5 mm3), glazed 106-µm-grit diamond-finished zirconia (3.8 ± 1.1 mm3), glazed as-sintered zirconia (3.5 ± 0.9 mm3), 46-µm-grit diamond-finished zirconia (1.7 ± 0.6 mm3), control (1.6 ± 0.7 mm3), glazed polished zirconia (1.4 ± 0.5 mm3), and solely polishing (0.4 ± 0.2 mm3). Even when polishing the surfaces before glazing, volume loss was not mitigated to the same extent as after polishing alone.

CONCLUSIONS

The zirconia surface condition beneath the glazing influences antagonist wear. Although polishing before glazing resulted in acceptable levels of antagonist wear, this approach did not yield as favorable results as polishing alone.

CLINICAL RELEVANCE

For operators favoring glazing, pre-polishing the zirconia surface could be advantageous to reduce wear.

Effect of different surface treatment protocols on the bond strength between lithium disilicate and resin cements

Because the use of hydrofluoric acid (HF) poses health risks if handled improperly, many clinicians prefer to have the ceramic restorations pre-etched in dental laboratories. However, during the try-in procedure, the pre-etched glass-ceramic restorations may be contaminated with saliva resulting in reduced bond strength. This in-vitro study aimed to investigate the effect of different surface treatments on the bond strength of lithium disilicate (LD) glass-ceramic restorations (IPS e.max Press, Ivoclar Vivadent) to two resin cements. One-hundred eighty blocks (4X4X3mm) of LD glass-ceramic were divided into twelve groups (n = 15), of which six received Variolink Esthetic DC (VE) cement and six received RelyX Ultimate (RU) cement, following the surface treatments: G1) Control: Hydrofluoric Acid + Silane (HF + Sil); G2) Hydrofluoric Acid + Saliva + Silane (HF + S + Sil); G3) Hydrofluoric Acid + Saliva + Ivoclean + Silane (HF + S + IC + Sil); G4) Hydrofluoric Acid + Saliva + Phosphoric Acid + Silane (HF + S + P + Sil); G5) Hydrofluoric Acid + Saliva + Monobond Etch & Prime (HF + S + EP); G6) Monobond Etch & Prime (EP). Following treatment, a resin-cement cylinder (2.3 mm diameter) was built on the glass-ceramic surface, photocured (20 s), stored in distilled water (37 °C, 24 h) and submitted to the shear bond strength test. Bond strength data (MPa) were subjected to two-way ANOVA and Tukey (α = 0.01). Cement type and surface treatment had a significant effect on the bond strength (p < 0.001) (Table 4). Single-step Monobond Etch & Prime (EP) significantly improved the bond strength of resin-cements to glass-ceramic with and without saliva contamination.

Interfacial fracture toughness of different surface treatments on zirconia-reinforced lithium silicate glass-ceramics

This study investigated the influence of different surface treatments on unfiring or firing zirconia-reinforced lithium silicate (ZLS) glass-ceramics. Celtra Duo and IPS e.max CAD blocks were cut and process following manufacturer protocols. The specimen surface was treated with seven different protocols. Two ceramic blocks with the same surface treatment were bonded with luting agent and prepared for mini-interfacial fracture toughness tests (mini-iFT). The specimens were tested after 1-week storage. The data was statistically analyzed using two-way ANOVA and Dunnett's T3 comparison (α=0.05). The highest mini-iFT of both Celtra Duo unfired and fired was shown in the HF+S group, which was not significantly different from HF+S+UA. For IPS e.max CAD, the mini-iFT was higher in the groups treated with hydrofluoric acid. Additional adhesive after silane application did not significantly improve bonding effectiveness. Therefore, surface treatment with hydrofluoric acid and silane is recommended for both unfiring and firing ZLS glass ceramics.

Effect of tribocorrosion on surface-treated titanium alloy implants: A systematic review with meta-analysis

The purpose of this systematic review and meta-analysis was to compare the results of tribocorrosion in titanium alloys of dental implants submitted to surface treatment with those whose treatment was not performed. An electronic search was carried out on the MEDLINE (PubMed), Web of Science, Virtual Health Library and Scopus databases. The search strategy used was PECO: Participants (P): titanium alloys; Exposure (E): surface treatment; Comparison (C): absence of surface treatment; and Result/Outcome (O): tribocorrosion. The search found a total of 336 articles, where 27 was selected by title or abstract, resulted to 10 after reading in full. The treatments that formed the rutile layer had better tribological results and therefore better protected the material from mechanical and chemical degradation, contrary to the technique with the addition of nanotubes. It was concluded that the surface treatment proves to be efficient to protect metals from mechanical and chemical wear.

Effect of surface treatments on optical, topographical and mechanical properties of CAD/CAM reinforced lithium silicate glass ceramics

OBJECTIVES

To investigate the effect of different surface treatments on optical, topographical and mechanical properties of CAD/CAM lithium silicate-based glass ceramics (LSC's) and their combined effect on the output of a light curing unit (LCU).

METHODS

Four CAD/CAM LSC's were investigated: Lithium Disilicate (Emax CAD; EC), Zirconia-reinforced silicates (Vita Suprinity; VS and Celtra Duo;CD) and Lithium Aluminum Disilicate (CEREC Tessera; CT). Ceramic specimens (n = 240) were divided into six subgroups according to their surface treatment: (a) Control, (b) Hydrofluoric acid (HF) 5%, (c) HF 5% + Neutralizing agent (N), (d) HF 9%, (e) HF 9% +N and (f) Self-etching ceramic primer (SEP). Irradiance, power and radiant exposure of a LCU were measured with MARC-LC following ceramic specimen interposition. Direct light transmission (T%) and absorbance (Abs%) of the specimens were measured with UV-Vis spectrophotometry. Roughness (Sa, Sq) and wettability (θ°) were measured with optical profilometry and sessile drop profile analysis, respectively. Biaxial flexural strength (σ) of the ceramic specimens was measured by the ball-on-three-balls method and ceramic specimens were examined microscopically. Statistical analyses was performed by two-way ANOVA followed by post hoc multiple comparisons (α = 0.05).

RESULTS

Acid neutralization decreased T% and increased Abs% in all LSC's and highest T% was exhibited with VS. Neutralized EC, VS and CD displayed higher Sa in HF9, while neutralized CT displayed higher Sa in HF5. Self-etch primer significantly reduced θ° (p < 0.001). σ was observed in the followed ascending order: HF9 +N < HF9 < HF5 +N < HF5 < SEP < Control for all LSC's.

SIGNIFICANCE

Optical, topographical and mechanical properties of the CAD/CAM ceramic blocks were strongly dependent on the type of surface treatment. Results of neutralization post-etching indicate promising potential for future investigations.

Effect of surface treatment on the repair bond strength of OMNICHROMA and Charisma Diamond ONE resin composites bonded to variable substrates

Objectives

To compare repair bond strength of OMNICHROMA and Charisma Diamond ONE resin composites bonded to variable composite substrates. Also, to evaluate the influence of different surface treatments on repair bond strength.

Methods

A total of 80-disc shaped specimens was fabricated using two resin based composite materials; IPS Empress Direct Enamel and OptiShade (n = 40). Substrate discs were thermocycle 5000 cycles then each substrate material was subdivided based on the surface treatment into two groups; air particle abrasion (APA) and silicon carbide grinding (SiCr) both groups followed by phosphoric acid etching. All groups received a single bond universal adhesive application prior to repairing with composite, in a smaller disc shape. All specimens were thermocycled for 10,000 cycles prior to shear bond strength testing and subsequent failure analysis. Statistical analyses were conducted and the level of statistical significance was set at 0.05.

Results

The comparison of mean values (considering the combination of the two types of substrates, surface treatments and repairing materials) showed a highly statistically significant difference in the shear bond strength among the eight study groups (p < 0.0001). The highest value of mean shear bond strength was associated with OptiShade substrates repaired by Diamond ONE (38.6 ± 2.4). Meanwhile, the lowest value was recorded for the SiCr treated OptiShade group repaired by Diamond ONE (13.6 ± 2.3). The failure analysis revealed that cohesive mode of failure was the most predominant.

Conclusion

Omnichroma showed higher repair bond strength values with SiCr surface treatment. Meanwhile, Charisma Diamond ONE had better bond strength with APA. Surface pretreatment had a significant impact on the repair bond strength where APA groups had significantly higher values compared to SiCr groups. Clinical Significance: Within the limitation of the present study; APA is recommended as surface pretreatment for improved bond strength in restorative composite repairs.

Ultrashort pulse laser patterning of zirconia (3Y-TZP) for enhanced adhesion to resin-matrix cements used in dentistry: An integrative review

Surface modification of yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) using lasers for adhesion enhancement with resin-matrix cement has been increasingly explored. However, Y-TZP is chemically inert and non-reactive, demanding surface modification using alternative approaches to enhance its bond strength to resin-matrix cements. The main aim of this study was to conduct an integrative review on the influence of ultrashort pulse laser patterning of zirconia (3Y-TZP) for enhanced bonding to resin-matrix cements. An electronic search was performed on web of science, SCOPUS, Pubmed/Medline, Google Scholar and EMBASE using a combination of the following search items: zirconia, 3Y-TZP, surface modification, laser surface treatment, AND laser, ultrashortpulse laser, bonding, adhesion, and resin cement. Articles published in the English language, up to January 2022, were included regarding the influence of surface patterning on bond strength of Y-TZP to resin-matrix cements. Out of the 12 studies selected for the present review 10 studies assessed femtosecond lasers while 2 studies assessed picosecond lasers. Ultrashort pulsed laser surface patterning successfully produced different surface morphological aspects without damaging the bulk properties of zirconia. Contrarily, defects such as micro-cracks occurs after surface modification using traditional methods such as grit-blasting or long-pulsed laser patterning. Ultrashort pulsed laser surface patterning increase bond strength of zirconia to resin-matrix cements and therefore such alternative physical method should be considered in dentistry. Also, surface defects were avoided using ultrashort pulsed laser surface patterning, which become the major advantage when compared with traditional physical methods or long pulse laser patterning.

Effect of airborne particle abrasion treatment of two types of 3D-printing resin materials for permanent restoration materials on flexural strength

OBJECTIVES

This study aimed to assess the effects of airborne-particle abrasion (APA) on the flexural strength of two types of 3D-printing resins for permanent restoration.

METHODS

Two types of 3D printing resins (urethane dimethacrylate oligomer; UDMA, ethoxylated bisphenol-A dimethacrylate; BEMA) constituting different components were printed. The specimen surfaces were subjected to APA using 50 and 110 µm alumina particles under different pressures. The three-point flexural strength was measured for each surface treatment group, and a Weibull analysis was performed. Surface characteristics were analyzed via surface roughness measurements and scanning electron microscopy. Dynamic mechanical analysis and nano-indentation measurements were limited to the control group.

RESULTS

The three-point flexural strength according to the surface treatment was significantly lower in the UDMA group for large particle sizes and at high pressures; the BEMA group demonstrated low flexural strength for large particle sizes regardless of the pressure. After thermocycling, the flexural strengths of UDMA and BEMA significantly decreased in the group subjected to surface treatment. The Weibull modulus and characteristic strength of UDMA were higher than those of BEMA under different APA and thermocycling conditions. As the abrasion pressure and particle size increased, a porous surface formed, and the surface roughness increased. Compared with BEMA, UDMA featured a lower strain, greater strain recovery, and a negligible increase in modulus according to strain.

SIGNIFICANCE

Thus, surface roughness increased with the sandblasting particle size and pressure of the 3D-printing resin. Hence, a suitable surface treatment method to improve adhesion can be determined by considering physical property changes.

Measurement of LYSO crystal light output and energy resolution improvement with acid etching

In this study, we investigated the impact of chemical etching on the light output and energy resolution of LYSO scintillators using simple, affordable laboratory equipment. We found that etching with phosphoric acid at temperatures between 180 °C and 190 °C improved the light output and energy resolution compared to mechanically polished crystals, even after minimal etching times. Our results show that with 7.5 min of chemical etching, the light output increase rate is 45.7%, and the relative energy resolution improvement is 12%.

PP/Jute Fiber Composites: Effect of Biological Route of Surface Treatment and Content of Jute on Composites

Jute as a fiber has many applications. It is also used in polymers as reinforcement due to its good tensile properties. However, when it is used in polymer matrices, there is a lack of adhesion between the polymer and jute fiber. Surface treatment of fiber using chemicals has been found to improve the properties. However, the use of chemicals causes environmental pollution, when these chemicals are discharged into the environment. In this paper, an attempt has been made to study the effect of the biological route to surface treat the jute fiber. The effect of surface treatment on the morphology of jute was examined. A comparative study was on the crystalline, thermal, and tensile fracture morphology of the composites to understand the effect of the incorporation of untreated and treated jute fibers in polypropylene (PP).

Influence of thickness and surface conditioning on fracture resistance of occlusal veneer

BACKGROUND

The purpose of the current study was to assess the impact of restoration thickness, surface conditioning and the interaction between them on the fracture resistance of CAD/CAM fabricated lithium disilicate occlusal veneers.

METHODS

A total of 42 maxillary molars were prepared to receive CAD/CAM fabricated lithium disilicate occlusal veneer either with 0.5 mm (n = 21) or 1 mm (n = 21) thickness. Each main group was divided into 3 subgroups (n = 7), according to surface treatment, HF acid (HF-1, HF-0.5), acidulated phosphate fluoride (APF-1, APF-0.5) and Monobond etch & prime (MON-1, MON-0.5). Multilinik N (Ivoclar-Vivadent) adhesive resin cement was used for bonding according to the manufacturer instructions. One hour after bonding, specimens were stored in water bath for 75 days followed by cyclic loading fatigue for 240,000 cycles to simulate clinical situation. Finally, specimens were fractured under compressive load in (N) using a universal testing machine. Two and one-way ANOVA and Post Hoc Tukey test were used for statistical analysis.

RESULTS

The means ± SD (N) fracture load for each group were calculated. MON-1 group showed the highest fracture load (1644.7 ± 155.3) followed by HF-1 group (1514.6 ± 212.5). Meanwhile, APF-0.5 showed the lowest fracture load (962 ± 249.6).

CONCLUSION

CAD/CAM fabricated lithium disilicate occlusal veneers can be used with a thickness of 0.5 mm instead of conventional crowns. Monobond etch & prime is recommended as a surface treatment for CAD/CAM fabricated lithium disilicate occlusal veneer due to biological hazards of Hydrofluoric acid.

Shear bond strength of orthodontic brackets bonded to a new version of zirconium all ceramic restoration: An in vitro comparative study

Objectives

Esthetic restorations such as monolithic zirconia crowns are highly requested for adults nowadays. Bonding orthodontic braces on this type of material became a challenge for orthodontists, because of the special surface treatment needed. This study aims to assess the shear bond strength (SBS) of metal, and ceramic brackets bonded on two types of zirconia ceramics, surface roughness (SR) after different surface treatments for their surfaces, and adhesive remnant index (ARI).

Materials and methods

Brackets' base surface area (BSA) was scanned by an extra-oral scanner, then measured. The doubled labial surface of monolithic zirconia crowns (n = 30) and monolithic high translucent zirconia crowns (n = 30) were prepared and each was divided into three groups (n = 10) depending on surface treatment (hydrofluoric acid etching, no treatment, and rocatec airborne abrasion). Extracted lower central incisors (n = 20) were prepared. Each of them was divided into two subgroups depending on the type of bracket bonded on their surfaces (metal and ceramic). The SR, SBS, and ARI were assessed.

Statistical analysis used

Tests used are independent-samples t-test, Fisher's exact test, One-Way ANOVA, and Kruskal-Wallis test.

Results

The highest SBS and SR were observed in Enamel/Metal and Zirconia/Metal/Rocatec subgroups, respectively.

Conclusion

Adequate bond strength could be obtained with the high translucent zirconia group if bonded with ceramic or metal brackets even if no treatment was used.

Clinical significance

A proportion of simulation was done like practicing inside the dental clinic to reach the best results regarding the adhesion strength of orthodontic brackets.

The effect of surface treatments on the adhesive bond in all-ceramic dental crowns using four-point bending and dynamic loading tests

The aim of this study was to determine the effect of sandblasting, grinding and plasma treatment on the adhesive bond strength between framework ceramic (Y-TZP) and veneering ceramic (feldspar ceramic). Therefore, four-point bending specimens (n = 180) were cut from densely sintered 3Y-TZP blanks. Subsequently, 80 of these samples received surface treatment by sandblasting and 80 samples by grinding. A reference group (20 samples) was not processed. Half of the specimens that received a surface treatment were additionally exposed to an oxygen plasma treatment. After processing, all specimens were manually veneered with feldspar ceramic and examined with a four-point bending test to evaluate the strain energy release rate G. The surface treatment parameters that achieved the highest and lowest G were transferred to real geometries of a posterior crown (n = 45). The crowns' ceramic framework was sandblasted and veneered by hand. The all-ceramic crowns were tested in a dynamic loading test and Wöhler curves were evaluated. Four-point bending samples blasted at an angle of 90° at 6 bar and a working distance of 1.5 cm without plasma treatment achieved the highest energy release rate. Samples blasted at an angle of 90° at 2 bar and a working distance of 1 cm with plasma treatment achieved the lowest energy release rate. Overall, plasma treatment did not improve bond strength. In the dynamic loading test, the group blasted with 2 bar showed the best results.

Integrating surface structure via triphenyl phosphate treatment to stabilize Li-rich Mn-based cathode materials

Li-rich Mn-based layered oxides (LLOs) have emerged as one of the most promising cathode materials for the next-generation lithium-ion batteries (LIBs) because of their high energy density, high specific capacity, and environmental friendliness. These materials, however, have drawbacks such as capacity degradation, low initial coulombic efficiency (ICE), voltage decay, and poor rate performance due to irreversible oxygen release and structural deterioration during cycling. Herein, we present a facile method of triphenyl phosphate (TPP) surface treatment to create an integrated surface structure on LLOs that includes oxygen vacancies, Li₃PO₄, and carbon. When used for LIBs, the treated LLOs show an increased initial coulombic efficiency (ICE) of 83.6% and capacity retention of 84.2% at 1C after 200 cycles. It is suggested that the enhanced performance of the treated LLOs can be attributed to the synergetic functions of each component in the integrated surface, such as the oxygen vacancy and Li₃PO₄ being able to inhibit the evolution of oxygen and accelerate the transport of lithium ions, while the carbon layer can restrain undesirable interfacial side reactions and reduce the dissolution of transition metals. Furthermore, electrochemical impedance spectroscopy (EIS) and galvanostatic intermittent titration technique (GITT) prove an enhanced kinetic property of the treated LLOs cathode, and ex-situ X-ray diffractometer shows a suppressed structural transformation of TPP-treated LLOs during the battery reaction. This study provides an effective strategy for constructing an integrated surface structure on LLOs to achieve high-energy cathode materials in LIBs.

Gas Plasma Surface Modification for Biological Assays

Surface chemistry plays an important role in the adsorption and immobilization of enzymes and antibodies. Gas plasma technology performs surface preparation that assists in the attachment of molecules. Surface chemistry helps to manage a material's wetting, joining, or the reproducibility of surface interactions. There are numerous examples of commerically available products that utilize gas plasma in their manufacturing process. Examples of products treated by gas plasma are well plates, microfluidic devices, membranes, fluid dispensers, and some medical devices. This chapter presents an overview of gas plasma technology and provides a guide for using gas plasma for designing surfaces in product development or research.

[Research on friction and wear behaviors of silicon-lithium spray coating on zirconia ceramics]

OBJECTIVE

To study microstructure, friction and wear behaviors of silicon-lithium spray coating on the surface of zirconia ceramics and to preliminarily evaluate its esthetic so as to provide support and guidance for the clinical application.

METHODS

Zirconia ceramic specimens were randomly divided into three groups: coating group (two subgroups), polishing group (two subgroups), and glazing group (four subgroups), with 10 samples in each subgroup. The two subgroups of coating group were the zirconia ceramics with the untreated and preliminary polishing surfaces sprayed with silicon-lithium coating, respectively. The two subgroups of polishing group were preliminary polishing and fine polishing of zirconia ceramics, respectively. The four subgroups of glazing group were preliminarily polished zirconia ceramics glazed with Biomic and Stain/Glaze products, respectively; and untreated zirconia ceramics glazed with Biomic and Stain/Glaze products, respectively. The above 8 subgroups of zirconia ceramic specimens were used as friction pairs with 80 steatite ceramics for 50 000 chewing cycles under 50 N vertical load and artificial saliva lubrication using chewing simulation. Scanning electron microscope was used to observe the microstructure of the surface and section of the coating group, and the thickness of the coating and glazing were measured. The linear roughness of the coating and polishing groups was mea-sured using a laser confocal scanning microscope. Vickers hardness was measured using a microhardness tester and the esthetic of zirconia ceramic full crown sprayed with silicon-lithium coating was preliminarily evaluated. White light interferometer was used to measure the width, the maximum depth and the volume of the wear scars of each group, and the wear depth of steatite ceramics and wear rate of zirconia ceramic specimens were calculated. Kruskal-Wallis nonparametric test and Dunn's multiple comparisons test were used to analyze the wear depth of each group (α=0.05).

RESULTS

The microstructures of the silica-lithium spray coatings on the untreated and preliminarily polished zirconia ceramic surfaces showed the protruding defects, and the line roughness of coating group was larger than that of the polishing group. The median thickness of the silica-lithium spray coating on the preliminarily polished zirconia ceramic was 13.0 μm (interquartile range, IQR: 11.6, 17.9), while that of the silica-lithium spray coating on the untreated zirconia ceramic was 4.4 μm (IQR: 4.1, 4.7). The Vickers hardness and wear rate of the coating group were between the polishing group and the glazing group. The wear depths of the wear scars of steatite ceramics were the glazing group, coating group, and polishing group in descending order, and there was statistically significant difference between glazing and polishing groups (P < 0.05). With the increase of polishing procedure, the wear depth of steatite ceramics decreased in each subgroups. The orders of maximum depth and volume of wear scars of zirconia ceramic were the glazing group, coating group, and polishing group in descending order, and there was statistically significant difference in the maximum depth of wear scars between glazing and polishing groups (P < 0.05).

CONCLUSION

The silica-lithium spray coating on the zirconia ceramic, can be used as a new method for zirconia ceramic surface treatment, because it can increase the esthetic of zirconia ceramics compared with polishing and reduce the wear of steatite ceramics compared with glazing.

Effect of orthodontic bonding with different surface treatments on color stability and translucency of full cubic stabilized zirconia after coffee thermocycling

Objective

To assess the color stability and translucency of full cubic stabilized zirconia (FSZ) following orthodontic bonding with different surface treatments and coffee thermocycling (CTC).

Methods

This in vitro study was conducted on 120 disc-shaped specimens of FSZ. Thirty specimens were selected as the control group and remained intact. The remaining specimens were randomly divided into three groups based on the type of surface treatment (n = 30): airborne particle abrasion (APA), silica-coating (CoJet), and carbon dioxide (CO₂) laser. After metal bracket bonding in the test groups, debonding and polishing were performed. Subsequently, all specimens underwent CTC (10,000 cycles). Color parameters, color difference (ΔE₀₀), and translucency parameter (TP) were measured three times at baseline (t0), after debonding and polishing (t1), and after CTC (t2). Data were statistically analyzed (α = 0.05).

Results

Significant difference existed among the groups regarding ΔE₀₀t0t2 (p < 0.001). The APA group showed minimum (ΔE₀₀ = 1.15 ± 0.53) and the control group showed maximum (ΔE₀₀ = 0.19 ± 0.02) color stability, with no significant difference between the laser and CoJet groups (p = 0.511). The four groups were significantly different regarding ∆TPt0t2 (p < 0.001). Maximal increases in TP were noted in the CoJet (1.00 ± 0.18) and APA (1.04 ± 0.38) groups while minimal increase was recorded in the control group (0.1 ± 0.02).

Conclusions

Orthodontic treatment makes zirconia restorations susceptible to discoloration and increased translucency. Nonetheless, the recorded ΔE₀₀ and ∆TP did not exceed the acceptability threshold.

Influence of Er:YAG laser irradiation on surface properties of Ti-6Al-4V machined and hydroxyapatite coated

Surface treatment by laser irradiation can change the topography of titanium; however, little is known about the changes it causes when applied to other coatings. This study aimed to evaluate the influence of Er:YAG laser irradiation on the surface properties of titanium-aluminum-vanadium (Ti-6Al-4V) discs. Four Ti-6Al-4V surfaces were evaluated (n = 10): CON-control, machined without surface treatment; LT-machined + laser treatment; HA-hydroxyapatite coating; and LT-HA-hydroxyapatite coating + laser treatment. For the laser treatment, an Er:YAG laser with a wavelength of 2940 nm, a frequency of 10 Hz, and an energy density of 12.8 J/cm2 was used. The morphology of the coating was investigated by scanning electron microscopy and the surface composition by energy-dispersive X-ray spectroscopy. The influence of laser irradiation treatment on roughness and wettability was also evaluated. The Er:YAG laser promoted a significant reduction in the roughness Sa (p < 0.05) and in the contact angle (p = 0.002) of the LT surface compared to the CON surface. On the LT-HA surface, a significant decrease in roughness was observed only for the Rz parameter (p = 0.015) and an increase in the contact angle (p < 0.001) compared to the HA surface. The use of the Er:YAG laser with the evaluated parameters decreased the surface roughness and improved the wetting capacity of machined without surface treatment. In the group with hydroxyapatite coating, the laser influenced the surface roughness only for the parameter Rz and reduced their wetting capacity.

Development of a clinical microarray system for genetic analysis screening

Objectives

Research on the relationship between diseases and genes and the advancement of genetic analysis technologies have made genetic testing in medical care possible. There are various methods for genetic testing, including PCR-based methods and next-generation sequencing; however, screening tests in clinical laboratories are becoming more diverse; therefore, novel measurement systems and equipment are required to meet the needs of each situation. In this study, we aimed to develop a novel microarray-based genetic analysis system that uses a Peltier element to overcome the issues of conventional microarrays, such as the long measurement time and high cost.

Methods

We constructed a microarray system to detect the UDP-glucuronosyltransferase gene polymorphisms UGT1A1*6 and UGT1A1*28 in patients eligible for irinotecan hydrochloride treatment for use in clinical laboratories. To evaluate the performance of the system, the hybridization temperature and reaction time were determined, and the results were compared with those obtained using a conventional hybridization oven.

Results

The hybridization temperature reached its target in 1/27th of the time required by the conventional system. We assessed 111 human clinical samples and found that our results agreed with those obtained using existing methods. The total time for the newly developed device was reduced by 85 min compared to that for existing methods, as the automated DNA microarray eliminates the time that existing methods spend on manual operation.

Conclusions

The surface treatment technology used in our system enables high-density and strong DNA fixation, allowing the construction of a measurement system suitable for clinical applications.

Biaxial flexure strength and physicochemical characterization of a CAD/CAM lithium disilicate ceramic: effect of etching time, silane, and adhesive applications

OBJECTIVE

To evaluate the effect of different acid etching time and bonding agent (silane and/or adhesive system) on biaxial flexural strength and physico-chemical properties of a lithium disilicate ceramic.

MATERIAL AND METHODS

One hundred twenty ceramic discs were made and divided into 8 groups (n = 15) according to factors "etching time" (20 and 120 s) with hydrofluoric acid (HF) and "bonding agent" (C, no bonding agent; S, silane, A, adhesive; and SA, silane + adhesive). After surface treatment, a resin cement layer was applied to the surface and all specimens were subjected to biaxial flexural strength (BFS) test with treated surfaces loaded in tension (1 mm/min). The Weibull analyses and complementary analyses were also performed. Statistical analysis was done with 2-way ANOVA and the Tukey test (α = 0.05).

RESULTS

ANOVA revealed that the factors "etching time" (p = 0.0003) and "bonding agent" (p = 0.007) were statistically significant. In the overall analysis, the HF120S group (272.02 ± 35.30A MPa) presented significantly higher BFS than that of HF120C (218.45 ± 17.15CD MPa) and HF20S (228.40 ± 37.83BCDMPa). On the other hand, the HF20A group (208.92 ± 31.16D MPa) had significantly lower BFS than HF120S (272.02 ± 35.30A), HF120A (254.42 ± 26.87ABC) and HF120SA (259.30 ± 36.55AB) groups (Tukey). The Weibull modulus (m) of all groups was significantly different from each other (p = 0.000).

CONCLUSIONS

Regardless of etching time, the application of silane alone is sufficient to increase the flexural strength of glass ceramic, eliminating the need for the application of adhesive systems. Moreover, if only silane or adhesive is applied, 120-s HF application should increase the flexural resistance of the lithium disilicate ceramic.

CLINICAL SIGNIFICANCE

Applications of adhesive systems after silanization can be suppressed from the surface treatment protocol of glass ceramics, since it does not improve their mechanical strength.

Current Protocols for Resin-Bonded Dental Ceramics

Resin-bonded ceramic restorations are common treatment options. Clinical longevity of resin-bonded ceramic restorations depends on the quality and durability of the resin-ceramic bond. The type and composition of the specific ceramic determines the selection of the most effective bonding protocol. Such protocol typically includes a surface pretreatment step followed by application of a priming agent. Understanding of fundamental ceramic properties and chemical compositions enables the clinician to make proper material selection decisions for clinically successful and long-lasting restorations. Based on research accrued over the past decades, this article reviews and discusses current resin-bonding protocols to most commonly used dental ceramics.

Effect of surface treatment on shear bond strength of relining material and 3D-printed denture base

PURPOSE

This study aimed to analyze the shear bond strength between the 3D-printed denture base and the chairside relining material, according to the surface treatment.

MATERIALS AND METHODS

Cylindrical specimens were prepared using DENTCA Denture Base II. The experimental groups were divided into 6 (n = 10): no surface treatment (C), Tokuyama Rebase II Normal adhesive (A), sandblasting (P), sandblasting and adhesive (PA), sandblasting and silane (PS), and the Rocatec system (PPS). After bonding the chairside relining material to the center of the specimens in a cylindrical shape, they were stored in distilled water for 24 hours. Shear bond strength was measured using a universal testing machine, and failure mode was analyzed with a scanning electron microscope. Shear bond strength values were analyzed using one-way analysis of variance, and Tukey’s honest significant difference test was used for post-hoc analysis (P < .05).

RESULTS

Group PPS exhibited significantly higher shear bond strength than all other groups. Groups P and PA displayed significantly higher bond strengths than the control group. There were no significant differences between groups PS and A compared to the control group. Regarding the failure mode, adhesive failure occurred primarily in groups C and A, and mixed failure mainly in groups P, PA, PS, and PPS.

CONCLUSION

The shear bond strength between the 3D-printed denture base and the chairside relining material exhibited significant differences according to the surface treatment methods. It is believed that excellent adhesive strength will be obtained when the Rocatec system is applied to 3D-printed dentures in clinical practice.

Strength and failure mechanism of single-lap magnesium-basalt fiber metal laminate adhesively bonded joints: Experimental and numerical assessments

A quick literature search reveals the significant lack of data and information concerning magnesium-to-magnesium bonded joints as well as fiber-metal laminates (FMLs) made with magnesium alloys. Therefore, a systematic series of experimental and numerical investigations are carried out to assess the performance of single-lap joints mating FML adherends. The primary goal is to better understand the effects of geometrical and material parameters that influence the performance of magnesium-to-magnesium joints. The FML adherends used in this study consist of basalt natural fiber-epoxy laminate sandwiched in between thin sheets of magnesium alloys, which were subsequently adhesively bonded using a room-cured epoxy resin. The effects of two types of surface treatments, namely, "sandblasting" and "sandblasting with resin coating" on the bond strength and failure mechanism of the adhesively bonded joints (ABJs) are investigated. A 3D numerical model developed to simulate the response of the joints subjected to quasi-static lap-shear tests. This model, which accounts for the material and geometrical nonlinearity in the joints, is used to perform a parametric analysis for establishing the optimal overlap bond length. The distributions of the shear and peel stresses in the overlap region and the effects of adhesive thickness on the performance of the joints are systematically examined. The comparison of the experimental data and numerical results confirms the robustness and cost-effectiveness of the numerical model in predicting the response of such single-lap ABJs.

Application of hybrid surface technology for improving sensitivity and peak shape of phosphorylated lipids such as phosphatidic acid and phosphatidylserine

The use of hybrid surface technology (HST), applied to the metal surfaces of an ACQUITY™ UPLC™ system and column, designed to mitigate the chelation, poor peak shape and analyte loss seen with acidic phospholipids was investigated. Compared to a conventional system significant improvements in both sensitivity, recovery and peak shape were obtained following UPLC on a CSH C18 column when the HST was used for the analysis of lysophosphatidic acid (LPA), phosphatidic acid (PA), lysophosphatidylserine (LPS), phosphatidylserine (PS), phosphatidylinositol-monophosphates (PIP), ceramide phosphate (CerP) and sphingoid base phosphate (SPBP). The benefits in chromatographic performance provided by the HST were seen particularly at low concentrations of these analytes. The HST system and column reduced peak tailing by 65-80% and peak width by 70-86% for LPA and PA. Moreover, increased signal intensities of up to 12.7 times were observed for LPA with the HST approach compared to the equivalent untreated LC system and column. The application of this methodology to the analysis of chicken egg PA and brain porcine PS extracts were accompanied by similar improvements in data quality.

Surface evolution of aluminosilicate glass fibers during dissolution: Influence of pH, solid-to-solution ratio and organic treatment

Materials made of synthetic vitreous mineral fibers, such as stone wool, are widely used in construction, in functional composites and as thermal and acoustic insulation. Chemical stability is an important parameter in assessing long term durability of the products. Stability is determined by fiber resistivity to dissolution, where the controlling parameters are solid surface area to solution volume ratio (S/V), pH and composition of the fibers and organic compounds used as binders. We investigated stone wool dissolution under flow through conditions, far from equilibrium, at pH range of 2 to 13, as well as under batch conditions, close to equilibrium, for up to 28 days, where S/V ranged from 100 to 10000 m^-1. The dissolution rate of stone wool shows minimum at pH 8.5 and increases significantly at pH < 4.5 and pH > 12. In close to equilibrium conditions, S/V defines the steady state concentration for the leached components. Decreased dissolution rate could result from evolution of a surface leached layer or the formation of secondary surface phases or both. We suggested three dissolution rate controlling mechanisms, which depend on pH. That is, dissolution is controlled by: a SiO₂ rich surface layer at pH < 4.5; by adsorption of an Al and Al-Si mixed surface layer at 5 < pH < 11 and by divalent cation adsorption and formation of secondary phases (silicates, hydroxides) at pH ∼ 13. The organic compounds, used to treat the stone wool fibers during manufacture, had no influence on their dissolution properties.

Surface modification of zirconia dental implants by laser texturing

The aim of this work was to perform an integrative literature review on the influence of laser irradiation on zirconia implants to enhance surface topographic aspects and the biological response for osseointegration. An electronic search was carried out on the PubMed database using the following search terms: "zirconia" AND "laser" AND "surface modification" OR "surface treatment" AND "dental implants" OR "bone" OR "osteoblast" OR "osseointegration." Of the identified articles, 12 studies were selected in this review. Results reported that the laser irradiation was capable of promoting changes on the zirconia surfaces regarding topographic aspects, roughness, and wettability. An increase in roughness was recorded at micro- and nano-scale and it resulted in an enhanced wettability and biological response. Also, adhesion, spreading, proliferation, and differentiation of osteogenic cells were also enhanced after laser irradiation mainly by using a femtosecond laser at 10nJ and 80 MHz. After 3 months of osseointegration, in vivo studies in dogs revealed a similar average percentage of bone-to-implant contact (BIC) on zirconia surfaces (around 47.9 ± 16%) when compared to standard titanium surfaces (61.73 ±16.27%), denoting that there is no significant difference between such different materials. The laser  approach revealed several parameters that can be used for zirconia surface modification such as irradiation intensity, time, and frequency. Laser irradiation parameters can be optimized and well-controlled to reach desirable surface morphologic aspects and biological response concerning the osseointegration process.

Efficiency of cold atmospheric plasma, cleaning powders and their combination for biofilm removal on two different titanium implant surfaces

Objectives

Biofilm removal is the decisive factor for the control of peri-implantitis. Cold atmospheric pressure plasma (CAP) can become an effective aid due to its ability to destroy and to inactivate bacterial biofilm residues. This study evaluated the cleaning efficiency of CAP, and air-polishing with glycine (APG) or erythritol (APE) containing powders alone or in combination with CAP (APG + CAP, APE + CAP) on sandblasted/acid etched, and anodised titanium implant surface.

Materials and methods

On respective titanium discs, a 7-day ex vivo human biofilm was grown. Afterwards, the samples were treated with CAP, APG, APE, APG + CAP, and APE + CAP. Sterile and untreated biofilm discs were used for verification. Directly after treatment and after 5 days of incubation in medium at 37 °C, samples were prepared for examination by fluorescence microscopy. The relative biofilm fluorescence was measured for quantitative analyses.

Results

Air-polishing with or without CAP removed biofilms effectively. The combination of air-polishing with CAP showed the best cleaning results compared to single treatments, even on day 5. Immediately after treatment, APE + CAP showed insignificant higher cleansing efficiency than APG + CAP.

Conclusions

CAP supports mechanical cleansing and disinfection to remove and inactivate microbial biofilm on implant surfaces significantly. Here, the type of the powder was not important. The highest cleansing results were obtained on sandblasted/etched surfaces.

Clinical relevance.

Microbial residuals impede wound healing and re-osseointegration after peri-implantitis treatment. Air-polishing treatment removes biofilms very effectively, but not completely. In combination with CAP, microbial free surfaces can be achieved. The tested treatment regime offers an advantage during treatment of peri-implantitis.

Silane-treated BaTiO3 ceramic powders for multilayer ceramic capacitor with enhanced dielectric properties

Silane/ceramic combination provides the composites with several advantages from the advancements of new ceramic composite materials with good thermal conductivity, high mechanical and dielectric properties have wide significant applications in electrical and electronic industries. In this study, to enhance the dispersibility of dielectric barium titanate (BaTiO₃) ceramic powder and additives for the fabrication of multilayer ceramic capacitors (MLCCs), surface treatment of the precursor of ceramic powder was performed using silane coupling agents. Dielectric ceramic sheets fabricated from ceramic powders that had been surface-treated with different amounts of N-[3-(trimethoxysilyl)propyl]aniline (TMSPA) which increased the surface gloss. In particular, the dielectric properties of the multilayer ceramic sheet fabricated by stacking sheets from the TMSPA-treated ceramic powder sintering at 1200 °C, it was confirmed that the dielectric constant increased from 881 to 2382 and the dielectric loss dropped from 1.96 to 1.34% with utilization of the TMSPA treatment. The physical and dielectric properties of the TMSPA-treated multilayer ceramic sheet were also determined by Fourier-transform infrared spectroscopy, X-ray diffraction, field-emission scanning electron microscopy, glossmetry, and electrochemical impedance analysis. The results revealed that the TMSPA-modified BaTiO₃ surfaces considerably increased the dielectric property of the fabricated nanocomposite.

An in vitro comparative evaluation of surface roughness characteristics of different orthodontic archwires: An atomic force microscopy study

Background. The present study evaluated and compared the surface roughness (SR) of five different types of orthodontic archwires made by two different manufacturers. Methods. In this in vitro study, 10 samples of five different archwires comprising of three types of shape memory wires, SmartArch (Ormco), Damon (Ormco), Heat-activated NiTi (HANT) (G&H Orthodontics), Stainless Steel wire (SS) (Ormco), and conventional NiTi (G&H Orthodontics) were examined by atomic force microscopy (AFM). The processing of 3D images was carried out using Gwyddion software, from which the root mean square (rms), the roughness average (Ra), and the maximum height (mh) of the scanned surface profile were documented. The data were analyzed with one-way ANOVA followed by post hoc Tukey tests for intergroup comparisons. Results. The mean SR of SS wires was the least (Ra=8.70±0.17), followed by NiTi wires (10.29±2.00) with a significant difference between them (P<0.05). Among the three shape-memory wires, the HANT wires had the least SR (Ra=22.97±16.56) compared to SmartArch wires (Ra=25.55±3.78) and Damon wires (Ra=25.67±4.54), but the difference was not significant (P>0.05). Conclusion. The SS wires by Ormco had the least SR followed by G&H orthodontics NiTi wires. The three different shape-memory wires tested had no significant difference in SR values.

Cold plasma surface treatments to prevent biofilm formation in food industries and medical sectors

Environmental conditions in food and medical fields enable the bacteria to attach and grow on surfaces leading to resistant bacterial biofilm formation. Indeed, the first step in biofilm formation is the bacterial irreversible adhesion. Controlling and inhibiting this adhesion is a passive approach to fight against biofilm development. This strategy is an interesting path in the inhibition of biofilm formation since it targets the first step of biofilm development. Those pathogenic structures are responsible for several foodborne diseases and nosocomial infections. Therefore, to face this public health threat, researchers employed cold plasma technologies in coating development. In this review, the different factors influencing the bacterial adhesion to a substrate are outlined. The goal is to present the passive coating strategies aiming to prevent biofilm formation via cold plasma treatments, highlighting antiadhesive elaborated surfaces. General aspects of surface treatment, including physico-chemical modification and application of cold plasma technologies, were also presented. KEY POINTS: • Factors surrounding pathogenic bacteria influence biofilm development. • Controlling bacterial adhesion prevents biofilm formation. • Materials can be coated via cold plasma to inhibit bacterial adhesion.

Artificial neural network-based smart aerogel glazing in low-energy buildings: A state-of-the-art review

Aerogel materials with super-insulating, visual-penetrable, and sound-proof properties are promising in buildings, whereas the coupling effect of various parameters in complex porous aerogels proposes challenges for thermal/visual performance prediction. Traditional physics-based models face challenges such as modeling complexity, heavy computational load, and inadaptability for long-term validation (owing to boundary condition change, degradation of thermophysical properties, and so on). In this study, a holistic review is conducted on aerogel production, components prefabrication, modeling development, single-, and multi-objective optimizations. Methodologies to quantify parameter uncertainties are reviewed, including interface energy balance, Rosseland approximation and Monte Carlo method. Novel aerogel integrated glazing systems with synergistic functions are demonstrated. Originalities include an innovative modeling approach, enhanced computational efficiency, and user-friendly interface for non-professionals or multidisciplinary research. In addition, human knowledge-based machine learning can reduce abundant data requirement, increase performance prediction reliability, and improve model interpretability, so as to promote advanced aerogel materials in smart and energy-efficient buildings.

A comparative study on high-efficient reduction of bromate in neutral solution using zero-valent Al treated by different procedures

Bromate, a toxic by-product of bromide-containing drinking water after disinfecting with ozone, has attracted much attention in the past two decades. Traditional methods to activate zero-valent metals for reducing bromate are to eliminate their surface oxide layer by acid washing. In this work, for the first time, zero-valent Al (ZVAl) was surface treated by the following procedures including soaking, soaking and freeze-drying, soaking and heat-treating, and γ-Al₂O₃ covering Al particle surfaces (GCAP). It was found that all of above surface treated ZVAls have an obvious high efficiency for bromate reduction relative to pristine ZVAl. The bromate reduction rate is GCAP > soaking Al > freeze-drying Al > soaking and heat-treating Al > pristine Al, and using GCAP just 30 min is taken to completely reduce bromate to bromide in neutral solution. Mechanism analyses revealed that Al surface treating or covered by fine γ-Al₂O₃ phase can promote the hydration and breakage of Al surface passive oxide layer, resulting in a fast contact of inner Al with outside ions, leading to a high reduction rate of bromate in neutral solution. XPS analyses indicated that there are no bromate or bromide ions adsorbed on Al particle surfaces, implying that there is a high direct donating efficiency of electrons from inner Al to bromate ions in solution. Furthermore, GCAP has a good reusability and >90% bromate can be reduced even it was reused up to 4 cycles.

Surface characterization of different surface treatments associations with plasma and bonding analysis of Y-TZP and the veneering ceramic

OBJECTIVES

To characterize the surface of zirconia (Y-TZP) submitted to different surface treatments (with and without plasma associations) and to evaluate the shear bond strength (SBS) between veneering ceramic (VC) and Y-TZP after different aging methods.

METHODS

301 Y-TZP specimens were fabricated and distributed into 7 groups: C (control): no treatment; Al: airborne abrasion with 27 μm Al₂O₃ particle; L: liner; P: plasma; Al + L: airborne + liner; Al + P: airborne + plasma; P + L: plasma + liner. The Y-TZP surface was characterized by SEM, EDS, AFM, surface profilometry, surface-free energy (SFE), and XRD. SBS between Y-TZP and VC was verified after three aging protocols: initial, after hydrothermal aging (autoclave for 5 h), or thermal fatigue (30,000 baths - 5-55 °C). One- (profilometry, SFE) and two-way ANOVA (SBS), and Tukey's HSD test were used.

RESULTS

For the plasma groups, a full globular surface coverage was observed (SEM, AFM). Si was found for Al, L, Al + L, and P + L. Roughness was lower for C, P, and Al + P. For SFE, the highest values were found when the liner was applied (>74.59 nm/Nm). The highest monoclinic content was observed for Al + L (6.96%) and Al + P (5.86%). For the initial period, Al and P + L presented the lowest SBS values (<5.85 MPa; P > 0.331). The highest SBS values were found for L, P, and P + L (hydrothermal aging) and for P, L, Al + L, and Al + P (thermal fatigue).

SIGNIFICANCE

Changes in Y-TZP topography and the SBS with the VC were found, according to treatments performed. Plasma treatment improved SBS and did not cause phase transformation.

Comparison of feldspathic veneer surface treatments on ceramic bracket SBS, ARI and surface roughness after different debonding/polishing methods: An in vitro study

OBJECTIVES

To analyse, in vitro, surface properties and the shear bond strength after debonding and polishing procedures of ceramic brackets directly bonded to 0.3-0.5-mm thick feldspathic veneers.

MATERIALS AND METHODS

Fifty six feldspathic ceramic veneers samples (0.3 to 0.5-mm thick) were allocated into groups according to veneers surface treatment procedures: (S) glaze layer was retained; (SHF) hydrofluoric (HF) acid etch; (SOXA) Al2O3 sandblasting; and (SB) diamond burs roughening. Specimens were treated with silane Monobond N® and ceramic brackets bonded with Transbond XT^®. Shear bonding strength (SBS) was assessed with a universal testing machine and ARI evaluated under a stereomicroscopic coupled to a digital camera. Remaining bonding composite was removed using a porcelain polishing kit and surface roughness assessed with a stylus profilometer.

RESULTS

No statistically significant differences were identified for SBS among the study groups (S, SHF, SOXA and SB) (P>0.05). The majority of the specimens presented ARI scores 3 and 2 (P>0.05). All of the study groups presented increased surface roughness after debonding and polishing procedures (P<0.05), with significant greater values observed in SB group (RaF: 1.27±0.41; RzF: 6.23±1.82), (P<0.05).

CONCLUSIONS

Surface treatment with hydrofluoric acid etch, Al₂O₃ sandblasting and diamond bur did not enhance SBS of orthodontic brackets bonded to ceramic veneers. Ceramic surfaces treated with diamond burs presented significantly increased roughness after adhesive removal.

Environmental impact assessment and enlightenment of surface treatment production line during operation

Industrial production creates material conditions for mankind, but also seriously pollutes the environment. In order to avoid pollution damage to the atmosphere, water, sound, and other environments, environmental impact assessments must be carried out before the project starts, and possible environmental pollution factors must be analyzed and predicted in advance. Company A, a manufacturer of mechanical parts, plans to build a new surface treatment production line, including two production links: anodizing and painting. The product coefficient method and the material balance method were used to evaluate and analyze the environmental pollution factors such as waste gas, wastewater, noise, solid waste, and discarded bath solution discharged during the operation period of the production line. The evaluation results show that after chromium mist recovery, spraying, filtration, and activated carbon adsorption and other measures are concentrated treatment, the concentration of various exhaust gas discharged in an organized manner is lower than the standard limit; various wastewater can be recycled after being filtered by ion exchange resin and activated carbon use, a very small amount of concentrated liquid needs to be handled by an external professional unit, and a cofferdam is installed under the production line and the ground is strengthened to prevent leakage, which will not pollute the groundwater environment; the noise level on the four plant boundaries during the operation of the production line meets the noise standard. No noise pollution will be generated; solid waste and discarded bath solutions are centrally stored by the enterprise and entrusted to an external professional unit for processing, and no other pollution will be generated.

Effect of supplemental acid-etching on the early stages of osseointegration: A preclinical model

PURPOSE

To evaluate the effect of two surface modifications on early osseointegration parameters of conical implants in a translational pre-clinical model.

MATERIALS AND METHODS

Conical implants with progressive trapezoidal threads and healing chambers were evaluated consisting of two different surface conditions: 1) Implacil surface (IMP Sur), and 2) Implacil surface + Supplemental Acid-etching (IMP Sur + AE). Surface characterization comprised of the evaluation of roughness parameters (S_a, S_q and S_dr), surface energy and contact angle. Subsequently, implants were installed in the ilium crest of nine female sheep (weighing ~65 kg). Torque out, histological and histomorphometric analyses were conducted after 3 and 6 weeks in-vivo. The percentage of bone to implant contact (%BIC) and bone area fraction occupancy within implant threads (%BAFO) were quantified, and the results were analyzed using a general linear mixed model analysis as function of surface treatment and time in-vivo.

RESULTS

Supplemental acid etching significantly increased S_a and S_q roughness parameters without compromising the surface energy or contact angle, and no significant differences with respect to S_dr. Torque-out testing yielded significantly higher values for IMP Sur + AE in comparison to the IMP Sur at 3- (62.78 ± 15 and 33.49 ± 15 N.cm, respectively) and 6-weeks (60.74 ± 15 and 39.80 ± 15 N.cm, respectively). Histological analyses depicted similar osseointegration features for both surfaces, where an intramembranous-type healing pattern was observed. At histomorphometric analyses, IMP Sur + AE implants yielded higher values of BIC in comparison to IMP Sur at 3- (40.48 ± 38 and 27.98 ± 38%, respectively) and 6-weeks (45.86 ± 38 and 34.46 ± 38%, respectively). Both groups exhibited a significant increase in %BAFO from 3 (~35%) to 6 weeks (~44%), with no significant differences between surface treatments.

CONCLUSION

Supplemental acid-etching and its interplay with implant thread design, positively influenced the BIC and torque-out resistance at early stages of osseointegration.

Effect of surface treatment on the mechanical stability of orthodontic miniscrews

OBJECTIVES

To provide collective quantitative evidence about the effect of surface treatments on the mechanical stability of orthodontic miniscrews (MSs).

MATERIALS AND METHODS

The study was registered in PROSPERO (No. CRD42020209652). The research question was defined according to the PICO (population, intervention, control, and outcomes) format. Various research databases were searched for animal and human studies on effects of surface treatment on the mechanical stability of MSs. Both prospective and retrospective in vivo clinical studies published in English were included. The risk of bias was assessed using SYRCLE's risk of bias tool for animal studies. The meta-analysis was conducted using RevMan 5.4.

RESULTS

A total of 109 articles were identified; 14 were included in the systematic review, and seven studies with sandblasting, acid etching (SLA) methods of surface treatment were included for meta-analysis. The number of study participants ranged from 6 to 24 (total n = 185), with a mean of 13.2. A total of 949 MSs were used with a mean of 67.8. The overall success rate for surface-treated MSs ranged from 47.9% to 100%. Forest plot of removal torque values showed significantly higher values for SLA surface-treated MSs compared with controls with a standard mean difference of 2.61 (95% confidence interval = 1.49-3.72, I2 = 85%). Forest plot of insertion torque showed a standard mean difference of -6.19 (95% confidence interval = -13.63-1.25, I2 = 98%, P = .10).

CONCLUSIONS

Surface treatment of MSs improved primary and secondary stability with good osseointegration at the bone-implant surface. However, significant heterogeneity across the studies included in the meta-analysis made it difficult to draw conclusions.

Resolving physical interactions between bacteria and nanotopographies with focused ion beam scanning electron microscopy

To robustly assess the antibacterial mechanisms of nanotopographies, it is critical to analyze the bacteria-nanotopography adhesion interface. Here, we utilize focused ion beam milling combined with scanning electron microscopy to generate three-dimensional reconstructions of Staphylococcus aureus or Escherichia coli interacting with nanotopographies. For the first time, 3D morphometric analysis has been exploited to quantify the intrinsic contact area between each nanostructure and the bacterial envelope, providing an objective framework from which to derive the possible antibacterial mechanisms of synthetic nanotopographies. Surfaces with nanostructure densities between 36 and 58 per μm² and tip diameters between 27 and 50 nm mediated envelope deformation and penetration, while surfaces with higher nanostructure densities (137 per μm²) induced envelope penetration and mechanical rupture, leading to marked reductions in cell volume due to cytosolic leakage. On nanotopographies with densities of 8 per μm² and tip diameters greater than 100 nm, bacteria predominantly adhered between nanostructures, resulting in cell impedance.

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Bacteria-nanotopography interactions can be quantified using FIB-SEM

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Envelope penetration and cell impedance are influenced by nanotopography density

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Low density nanotopographies (8 per μm²) mediate cell impedance

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High-density nanotopographies (36–137 per μm²) mediate deformation and penetration

Improved osteogenesis and angiogenesis of theranostic ions doped calcium phosphates (CaPs) by a simple surface treatment process: A state-of-the-art study

Surface treatment of biomaterials could enable reliable and quick cellular responses and accelerate the healing of the host tissue. Here, a series of calcium phosphates (CaPs) were surface treated by hydrogen peroxide (H₂O₂) and the treatment effects were physicochemically and biologically evaluated. For this aim, as-synthesized CaPs doped with strontium (Sr²⁺), iron (Fe²⁺), silicon (Si⁴⁺), and titanium (Ti⁴⁺) ions were sonicated in H₂O₂ media. The results showed that the specific surface area and zeta potential values of the surface-treated CaPs were increased by ~50% and 25%, respectively. Moreover, the particle size and the band-gap (Eg) values of the surface-treated CaPs were decreased by ~25% and ~2-10%, respectively. The concentration of oxygen vacancies was increased in the surface-treated samples, which was confirmed by the result of ultraviolet (UV), photoluminescence (PL), Commission Internationale de l'éclairage (CIE 1931), and X-ray photoelectron spectroscopy (XPS) analyses. In vitro cellular assessments of surface-treated CaPs exhibited an improvement in cytocompatibility, reactive oxygen species generation (ROS) capacity, bone nodule formation, and the migration of cells up to ~8%, 20%, 35%, and 13%, respectively. Based on the obtained data, it can be stated that improved physicochemical properties of H₂O₂-treated CaPs could increase the ROS generation and subsequently enhance the biological activities. In summary, the results demonstrate the notable effect of the H₂O₂ surface treatment method on improving surface properties and biological performance of CaPs.

Influence of photodynamic therapy and different conventional methods on conditioning of lithium di silicate ceramics bonded to metallic brackets: An assessment of bond strength

AIM

The aim of the current study was to assess the effect of different conditioning methods on Lithium di silicate (LDC) employing conventional and contemporary regimes bonded to metallic brackets.

MATERIAL AND METHODS

70 discs of LDC were prepared and polished to attain smooth surface. Samples were allocated into seven groups according to ceramic surface conditioning. Group 1 surface treated with Er-YAG laser and saline (S), Group 2 PDT using MBP + S, Group 3 H F + S (control), Group 3 HF (Hydrofluoric acid) + saline, Group 4 HF (Hydrofluoric acid) + ultrasonic bath (UB) + S, Group 5 sand blasting the glass ceramic surface with 120 um Al₂O₃, Group 6 LDC surface conditioned with SECP(Etch and Prime) and Group 7 ECL(Laser) + S on was irradiated on LDC. Both chemical and mechanical surface treatments of LDC were followed by placement of metallic brackets. Samples were arranged in universal testing machine for shear bond strength (SBS) testing. Bond failure of brackets were assessed using ARI. To assess and compare the mean and standard deviations (SD) among experimental groups analysis of variance (ANOVA) was employed. All treatment combination means were compared using the post hoc Tukey's multiple comparison test at a significance level of (p ≤ 0.05).

RESULTS

SBS values of Group 2 H F acid + S displayed highest bond durability (22.28 ± 1.09 MPa). Whereas, specimens in Group 4 surface treated with 120 μm Al₂O₃ displayed lowest SBS scores (11.81 ± 0.55 MPa) and these bond scores were comparable to PDT using MBP + S (12.54 ± 1.09 MPa) (p > 0.05). LDC surface treated by ECL + S (21.11 ± 3.85 MPa), HF + UB + S (19.28 ± 0.52 MPa) exhibited results comparable to HF acid + S (p > 0.05).

CONCLUSION

LDC conditioned with HFS still remains as gold standard. Use of PDT for surface treatment of LDC and bonded to metallic bracket is not recommended as it results in decreased bond durability. Use of ECL-S and HF + UB + S has a potential to be used alternatively to HFS for LDC conditioning.

Effect of different surface treatments on the biaxial flexure strength, Weibull characteristics, roughness, and surface topography of bonded CAD/CAM silica-based ceramics

OBJECTIVE

To investigate the influence of different surface treatments on biaxial flexure strength, roughness, and surface topography of lithium silicate/disilicate-based ceramics.

METHODS

225 discs (∅: 12 mm; 1.2 mm - ISO 6872) were made from three ceramics: IPS e.max CAD (LD - Ivoclar Vivadent), Suprinity (LSS - Vita) and Celtra Duo (LSC - Dentsply). The samples were randomly divided into 5 groups (n = 15): no treatment (C); 10% hydrofluoric acid + silane (HF); sandblasting Al₂O₃ + silane (SB); silicatization + silane (SC); and self-etching ceramic primer (SEP). After surface treatment, a resin cement layer was applied to the disc surface (RelyX U200, 3M ESPE), mechanical cycled (1.2 × 10⁶ cycles, 50 N, 3.8 Hz) and submitted to biaxial flexural strength test (1 mm/min, 1000 Kgf). Roughness, EDS and SEM were also performed. Data were analyzed by one-way ANOVA, Tukey test (5%) and Weibull.

RESULTS

ANOVA revealed that the "surface treatment" factor was significant for all ceramics (p < 0.05). The groups LD-HF (289.30 ± 40) LD-SEP (298. 87 ± 53.29), LSC-HF (195.51 ± 42.12), LSS-HF (269.58 ± 27.07) and LSS-SEP (207.45 ± 28.63) presented significantly higher biaxial flexure strength than respective control groups, except for the LSC-SEP (165.41 ± 33.86), which was statistically similar to the control. The Weibull modulus was significantly higher for the LD-SB, LSC-SC groups. Additionally, the LD-SB, LSC-SC and LSS-HF groups showed higher roughness compared to the other treatments.

SIGNIFICANCE

HF etching followed by silanization and self-etching ceramic primer are the most suitable surface treatments for lithium silicate/disilicate-based glass-ceramics.

Effect of etching with low concentration hydrofluoric acid on the bond strength of CAD/CAM resin block

The effect of etching for 90 s with low concentrations (0.5, 1.0, 2.0, 3.0, 3.5, and 4.0%) of hydrofluoric acid (HF) on the adhesiveness of computer-aided design/computer-aided manufacturing (CAD/CAM) resin blocks [CERASMART (CS), SHOFU BLOCK HC (HC), KATANA AVENCIA Block(KA), and VITA ENAMIC (EN)] was investigated. Energy dispersive spectroscopy revealed that the silicon content of HC, KA, and EN groups remained almost constant with HF etching of ≤4%. HF etching increased the surface roughness of all blocks. The HF concentration resulting in the highest shear bond strength in each group was as follows: CS (2.0%), HC (3.0%), KA (3.5%) and EN (0.5%). Scanning electron microscopy revealed that the bonding interface of etched surfaces differed significantly from that of airborne-particle abrasion surfaces. Thus, low concentration HF etching is effective for surface treatment of CAD/CAM resin blocks. The etching effect and optimum HF concentration differ with the block composition and structure.

Characterization of ligno-cellulosic fiber extracted from Atriplex halimus L. plant

Lignocellulosic fiber extracted from saltbush (Atriplex halimus L.) is characterized as reinforcement of composite materials. The morphological, physical, thermal and mechanical properties of fibers were addressed for the first time in this paper. The fibers were also subjected to chemical analysis. Stems were boiled in 0.5% sodium hydroxide (NaOH) or 10% sodium bicarbonate (NaHCO₃). Optical and scanning electron microscopy images show an abundance of fiber in the form of thick-walled polygonal tubes. NaOH treatment yielded rough-surfaced fibers whereas the NaHCO₃ treatment yielded smooth-surfaced fiber. Attenuated total reflectance Fourier transform infrared analysis revealed that NaOH treatment removed amorphous components. Based on x-ray diffraction, the crystallinity index increased from 55% to 57%. Thermogravimetry and differential scanning calorimetry showed that the fiber was thermally stable up to 220 °C and 235 °C with activation energies of 56 kJ/mol and 72 kJ/mol respectively for bicarbonate-treated and NaOH-treated material. In single-fiber tensile tests, the latter was stronger, with a Young's modulus of up to 19 GPa and tensile strength of 229 MPa.

The effect of repeated surface treatment of zirconia on its bond strength to resin cement

PURPOSE

The aim of this study is to evaluate the influence of repeated surface treatments on wettability and surface roughness for zirconia surface and bond strength of zirconia-based ceramics to resin cement.

MATERIALS AND METHODS

Seventy blocks (10 × 10 × 3 mm) of zirconia-based ceramics were fabricated and divided into two groups according to the surface treatments: (A) 110 µm Al₂O₃ airborne-particle abrasion and (R) 110 µm silica modified Al₂O₃ airborne-particle abrasion. At stage 2, each group was subdivided into 5 groups according to the surface retreatments: (a) 110 µm Al₂O₃ airborne-particle abrasion, (r) 110 µm silica modified Al₂O₃ airborne-particle abrasion, (D) diamond bur, (Da) diamond bur + 110 µm Al₂O₃ airborne-particle abrasion, and (Dr) diamond bur + 110 µm silica modified Al₂O₃ airborne-particle abrasion. Cylinders of self-adhesive resin cement were cemented onto each treated ceramic surface and subjected to micro-shear bond strength test. Additional specimens were prepared for roughness and wettability analyses. The data were subjected to t-test and One-way ANOVA followed by Tukey's post hoc test (α=.05).

RESULTS

At stage 1, group R presented higher bond strength values than group A (P=.000). There was a statistically significant increase of bond strength at stage 2 for group A (P=.003). The diamond bur influenced the surface roughness, increasing the values (P=.023). Group R provided better wettability. Regardless of the applied surface treatment, most of failures were adhesive.

CONCLUSION

The combination of application and reapplication of Rocatec Plus showed the best results of bond strength. Surface retreatment and recementation might be an indicated clinical strategy.

Bonding of conventional provisional resin to 3D printed resin: the role of surface treatments and type of repair resins

PURPOSE

This study evaluated the shear bond strength between 3D printed provisional resin and conventional provisional resin depending on type of conventional provisional resin and different surface treatments of 3D printed resin.

MATERIALS AND METHODS

Ninety-six disc-shaped specimens (Ø14 mm × 20 mm thickness) were printed with resin for 3D printing (Nextdent C&B, Vertex-Dental B. V., Soesterberg, Netherlands). After post-processing, the specimens were randomly divided into 8 groups (n=12) according to two types of conventional repair resin (methylmethacrylate and bis-acryl composite) and four different surface treatments: no additional treatment, air abrasion, soaking in methylmethacrylate (MMA) monomer, and soaking in MMA monomer after air abrasion. After surface treatment, each repair resin was bonded in cylindrical shape using a silicone mold. Specimens were stored in 37℃ distilled water for 24 hours. The shear bond strength was measured using a universal testing machine at a crosshead speed of 0.5 mm/min. Failure modes were analyzed by scanning electron microscope. Statistical analysis was done using one-way ANOVA test and Kruskal-Wallis test (α=.05).

RESULTS

The group repaired with bis-acryl composite without additional surface treatment showed the highest mean shear bond strength. It was significantly higher than all four groups repaired with methylmethacrylate (P<.05). Additional surface treatments, neither mechanical nor chemical, increased the shear bond strength within methylmethacrylate groups and bis-acryl composite groups (P>.05). Failure mode analysis showed that cohesive failure was most frequent in both methylmethacrylate and bis-acryl composite groups.

CONCLUSION

Our results suggest that when repairing 3D printed provisional restoration with conventional provisional resin, repair with bis-acryl composite without additional surface treatment is recommended.